Ignition apparatus



Feb. 22,

E. B. NOWOSIELSKI IGNITION APPARATUS Original 'Filedfiuly 2. 1955 Fig.5

'HHHHHHHII I INVENTOR.

Edward .B. A/owos//skf 1i; 4.. M 4

Patented Feb. 22, 1938 UNITED STATES PATENT OFFICE IGNITION APPARATUS Edward B. Nowosielski, Bloomfield, N. J., assignor to Eclipse Aviation Corporation, East Orange,

N. J., a corporation of New Jersey Original application July 2, 1935, Serial No. 29,-

530. Divided and this application January 18, 1937, Serial No. 121,217

9 Claims. (Cl. 123-169) This invention relates to spark-plugs, and more specially to spark-plugs for aviation engines. e severe service conditions which are imposed n spark-plugs for air-plane motors are familiar assembly to be further described. It will be noticed that the spindle M2 extends upwardly to a point just above the end of the gland I! and, due to the reduction in cross-sectional area at 5 to those skilled in the art, as is also the importhis point, and also by reason of the termination 5 tance of enclosing all parts of the high-tension of the copper jacket it at this point, there is a current-carrying system by a continuous metaltendency to cut off much of the upward flow 110 shield to prevent interference with the recepof heat through the spindle l l2 and to deflect the tion of signals by adjacent radio receiving sets, heat flow outwardly and radially into the copper and also to protect the exposed parts of the iggland ll from which much of the heat is directly 1o nitlon system from detriment by the elements or dissipated by the cooling blast circulating in otherwise. chamber is by reason of the radial openings The object of this invention is to provide a in the metallic shell ll. spark-plug, and more especially a shielded spark- As a means of maintaining the mica stacl: M

plug, the construction ofwhich is such as to proin the compressed condition and also applying 15 long its life and to insure its effectiveness in such radial pressure to hold the mica lining l5 of the service, and toafford convenience and economy inner metallic sleeve i l in position, and at the in manufacture. same time effecting an additional path for the The invention comprises novel features of great transfer of heat directly to the said sleeve it 0 utility in spark-plugs, and novel combinations of from which it may be radiated to the atmosphere elements making an improved spark-plug and by the cooling current of air flowing along the an improved assemblage of the spark plug and chamber it to and from the radial apertures 32, its high-tension conductor. This application is the embodiment shown in Fig. 1 includes cap and a division of my application No. 29,530, filed July retainer elements lid and l ill to permit the use 2, 1935. of a method of assembly which results in a more 25 Some of the objects are to provide an improved secure positioning of the mica insulation. As core construction including novel methods of shown, the method of assembly is to first insert constructing and assembling the core; to provide the retainer M8 over the previously positioned improved heat deflecting and cooling means"; and mica parts 48 and t6 and. due to the internal to provide improvements in the manner of intaper on the member Mil this act of inserting 3Q sulating the current. the said member will operate to tend to turn in- In the drawing, wardly the upper extending end of the mica wrap- Figures 1 and 2 are views partly in elevation per 46. After this has been done the cap lid is and partly in section, each figure illustrating a inserted, the lower end of the stem thereof being somewhat different embodiment of the invention. slightly beveled to facilitate its passing the upper 35 In many respects both embodiments correspond edge of the mica wrapper. Then as the stem deto the disclosure in my copending application No. scends it exerts a tightening action upon the up- 16,882, filed April 17, 1935, and this is particularper portion of the mica wrapper Alli due to its 1y true of the features indicated in elevation in having a slightly larger external diameter the two embodiments; and where identical elethat of the inwardly bent portion of the mica 4o ments appear in the two embodiments they are wrapper. When fully inserted the radially exdesignated by similar reference numerals. tending portion of the cap seats itself upon the First describing-Figure 1, reference character annular ledge in the retainer H8 with its upper l l designates a metallic extension of the metallic surface flush withthe upper surface of said body ill. As shown this part II extends upwardly ber, and thereby making it possible to apply a 45 to enclose the spindle H2 and the electrical concompressing force to both said elements which nection between the same and the conductor may be transmitted to the mica assembly 48 but which leads the high-tensioncurrent to the spinwithout disturbing the upper end of the mica die. This vshield extensionlis preferably in one wrapper 46 due to the slight annular clearance 50 piece with the attaching nut ;5, though such unity indicated at E22. 50 is not necessary. The spring seat I l3 of Fig. l rests upon an an- I provide a cooling and ventilating chamber l3 nular rim W6 formed by recessing the upper end in the form of an annular space between the of spindle H2. An asbestos disk W5 is inserted shield extension II and a long thin cylindrical in this recessed end to aid in deflecting the heat metallic sleeve I having low thermal conductivflow away from spring 6!. 55 lty, and lined with a tube I5 formed of rolled In the embodiment of Fig. 2 the Spindle W mica constituting the wall of a second chamber eludes an upp thiniwalled Section l3! and an IE bounded at its lower end by the upper surface pp ps end portion of slightly thicker of the compressible metal gland I1, and at its cross -section to p v d additional S e t along upper end by a novel heat deflecting and sealing the surface of contact with the retainer ring I33, 50

- and which receives a washer I54 against which the upper end I32 of the spindle is upset in the process of applying pressure to the parts I54 and I33 and thus to the washer IB'l and mica assembly 48. Otherwise this construction resembles that of Fig. 1, including the use of a stem H58 having a fiat base I56 resting upon thespring Bi. These parts I33 and I54, when subjected to this upsetting pressure applied to the spindle top, not upon the washer I51 to compress the mica steel: and at the same time press against the expansion ring 86! to cause the latter to grip the mica lining to at a point approximately midway between its ends, this ring iii being inserted and expanded against the lining I5 prior to the assembly of said tube within the shield extension By the process above described the cap as= sembly and spindle, that is, the parts it, i5 5, i853 and ibl become a permanently integrated unit which, by reason of its extremely tight fit with the ring N36, is capable oi transferring consider able heat from the upper part of the plug to the radiator tube i4. This-heat transfer is acceler= ated by reason of the shunting effect of the asbestos heat barrier I59, there being a similar asbestos heat barrier shown in Fig. 1.

After the cap assembly has been secured by the upsetting process above described, coil spring 6i, and stem I58 are inserted in position to-con tact the radially spread strands of the current conducting wire 66 when the latter is installed in place. Associated with the wire 68 is its covering 61 of insulating material, its outer metallic sheath 68, the swivel connection 69 soldered or otherwise secured thereto, and the detachable coupling nut Ii, all of which are brought into assembled relationship with the parts previously described, by reason 01' the co-operating threads at the top of shell II.

Various changes, which will now appear to those skilled in the art, may be made in the form, details of construction and arrangement of the parts without departing from the spirit of the invention, and reference is therefore to be had to the appended claims for a definition of the limits of the invention.

What is claimed is:-

1. In a spark plug having a central spindle, a wrapper of insulating material around the spindle, a stack of insulating discs surrounding said wrapper, and means for enclosing and protecting the upper edges of said wrapper, said means including a stack retaining member having a tapered bore fitting around said wrapper, and a' second member having an externally tapered shank fitting within said wrapper, and also having a head above said wrapper, said head being supported by said stack retaining member.

2. A spark plug having the elements recited in claim 1, and characterized by the fact that the insulating wrapper is: bent inwardly by the pressure of the stack retaining member upon the outer wall thereof, and is thereafter maintained in said bentcondition under the oppositely directed pressures, first, of the stack retaining member, and secondly, oi the externally tapered shank of said second member.

3. A spark-plug comprising the combination of .a central spindle, a. mica sleeve'about said spindle, a bodyin which the spindle and its mica sleeve are fixed, a barrel extending upward from said 4. A spark-plug comprising the combination of a central spindle, a sleeve about said spindle, a body in which the spindle and its sleeve are fixed,

an insulated high-tension conductor, a sleeve lining said barrel, a stack of washers occupying space between said sleeves and bearing on a shoulder of the body, and means above, and spaced from, the upper end of the spindle confining said stack.

5. In a spark plug having a central spindle, a sleeve of insulating material around the spindie, a stack of insulating discs surrounding said sleeve, and means for enclosing and protecting the upper end of said sleeve, said means including a steel; retaining member having a tapered bore fitting around said sleeve, and a second member having an externally tapered shank fitting within said sleeve, and also having a head above said sleeve, said head beingsupported by said stack retaining member.

6. in a spark plug having a central spindle, a sleeve of insulating material around the spindle, a stack of insulating discs surrounding said sleeve, and means for enclosing and protecting the upper end of said sleeve, said means including a stack retaining member having a tapered bore fitting around said sleeve, and a second member engageable with said sleeve and supported by said stack retaining member, said two members co-operating to hold said sleeve in fixed relation thereto.

7. In a spark plug having a central spindle, a wrapper of insulating material around the spindle, s stack of insulating discs surrounding said wrapper, and means for enclosing and protecting the upper edges'of said wrapper, said means including a stack retaining member having a tapered bore fitting around said wrapper, and a second member engageable with said wrapper and supported by said stack retaining member. said two members co-operating to hold said wrapper in fixed relation thereto.

8. In a spark plug having a central spindle, a wrapper of insulating material around the spindle, "a body of insulating material surrounding said wrapper, and means for enclosing and protecting the upper edges of said wrapper, said means including a body engaging member having at tapered bore fitting around said wrapper, and asecond member having an externally tapered shank fitting within said wrapper, said two members cooperating to hold said wrapper in fixed-relation thereto.

9. In a spark plug having a central spindle, a sleeve of insulating material around the spindle,

a body of. insulating material surrounding said sleeve,. and means for enclosing and protecting the upper end of said sleeve, said means including'a body engaging member having a tapered bore fitting around said sleeve, and a second member supported by said body engaging memher, and cooperating therewith to hold said sleeve in fixed relation thereto.

" EDWARD B. nowosmrsxr.

a barrel extending upward from said body above the spindle to form a socket for the insertion of 

